in the percentage of fatty acids in oysters after HPP at 260, 500 and
800 MPa. Also coinciding with our results,Rodríguez-Alcalá, Harte,
and Fontecha (2009)found no changes in the proportions of fatty
acids, in general, nor in those of CLA, in particular, in high pressure
homogenized cow’s, ewe’s or goat’s milks. CLA isomers can easily
suffer from isomerisation processes due to temperature, resulting
in altered ratio between isomers. The present results indicate that
pressure does not cause appreciable isomerisation of CLA in human
milk.
The fact that proportions of fatty acids, including those of LCPUFAs and CLA, are not affected by either Holder pasteurisation
or HPP indicates that infants receiving donor human milk treated
by either of these two techniques would not be deprived of these
crucial milk components. However, and contrary to pasteurisation, no study has yet assessed the stability of milk lipases after
HPP; moreover, the analysis of fatty acids, as performed in our
study, quantifies not only fatty acids in lipid structures (triglycerides, phospholipids) but also free fatty acids, which means that